1. Field of the Invention
The present invention relates to a laser optics device having a semiconductor laser and at least an optical lens positioned a defined distance from the semiconductor laser and defining an optical axis together with the semiconductor laser. In optical devices of this type it is essential that the semiconductor laser and the lens or the lens system be axially aligned as precisely as possible and during the whole period of operation. The operation of a semiconductor laser mostly is connected with substantial heat development which leads to thermal expansion of the semiconductor laser itself and of the surrounding elements as e.g. the lenses. If the semiconductor laser is fixedly mounted, it easily may be damaged and/or the laser beam may be displaced because of such thermal expansion. If, on the other hand, the semiconductor laser is supported so that thermal expansions can be absorbed, its alignment to the optical axis may be affected which makes it necessary to repeatedly adjust the laser optics.
2. Description of the Prior Art
A known laser optics device of this type is disclosed in the UK-patent specification no. 2,087,591. The semiconductor laser, as well as the lens system, are mounted within a holder. The lenses are positioned radially and very accurately within said holder. In an axial direction the lenses are positioned by means of locking elements fixed to the holder. In this construction nothing is provided to compensate for the effect of thermal expansion after a longer period of operation.
In the European patent publication no. 0 397 171 an optical device is disclosed in which two ball lenses and a light emitting diode 5 are fitted within a casing consisting of two identical halves molded from the same mold. Thereby, possible molding errors can be compensated and any molding imperfections will influence the optical precision of the device. However, no measures are disclosed to avoid the influences of thermal expansion on the precision of the alignment of the elements.